so i recently changed out my filter and cleaned the prescreen. I've driven over 100 miles now and I cant get the WVO to come up to pressure. D2 is going backwards through the system, in auto it says low pressure but the WVO pump is running. usually running it in manual for a bit fixes this like its priming the system, but this hasn't done anything. I dk if the check valve is stuck open or the pressure switch is stuck open. if anyone has any ideas on how to fix I would love to hear them.

all I have done so far is take out the prescreen entirely to see if it was jammed in there and that didn't fix anything so far. also to note I am using a napa equivalent of the Donaldson filter which has worked before and I usually don't have any issues with those filters.

pull and clean the pressure regulator. There may be something jammed in there. Check to make sure your tank isn't building vacuum.

pull the line from the back of the manifold and run to a remote tank to eliminate a clog somewhere before the manifold.

Some have also said that cracking the filter can help if it is just being difficult to prime. This will be messy, but worth a shot.

how do you know WVO is going backwards through the system? I believe if you are running on auto and under pressure the return solenoid is still sending fuel to the Veggie tank. This would explain diesel in the veg tank.

If you really have wvo running backwards through your system them you definitely need to change it.

I am not sure if the dodge systems are the same as powerstrokes but if diesel is coming back to Wvo tank in the return line your purge valve is sticking open. You could pinch line with a vise grip and see if that helps build pressure

it's different. Pinching the return line will just make the truck run really rough. It isn't a purge it's a return selector on the Dodge. Either return to veg tank or return to diesel tank it is always returning to one of the tanks.